Copy of Physics 2 Lab 9

Data: Data Table 1 The Law of Reflection Angle of: Incidence (Right of Normal) Angle of: Reflection # 1 Angle of: Incidence (Left of Normal) Angle of: Reflection #2 0° 0 0° 0 10° 10 10° 10 20° 20 20° 20 30° 30 30° 30 40° 40 40° 40 50° 50 50° 50 60° 60 60° 60 70° 70 70° 70 80° 80 80° 80 90° 90 (doesn’t really touch the mirror) 90° 90

Data Table 3 50 mm Concave Spherical Mirror d o (mm) d i (mm) h i (mm) h o (mm) 1/ f (1/ d i + 1/ d o ) f h i / h o - d i / d o 500 84 3 19 0.01390476 71.917808 22 0.15789473 7 -0.168 450 85 3 19 0.01398693 71.495327 1 0.15789473 7 -0.18888888 9 400 86 3 19 0.01412791 70.781893 0.15789473 7 -0.215 350 88 3 19 0.01422078 70.319634 7 0.15789473 7 -0.25142857 1 300 89 4 19 0.01456929 68.637532 13 0.21052631 6 -0.29666666 7 250 93 5 19 0.01475269 67.784256 56 0.26315789 5 -0.372 200 99 8 19 0.01510101 66.220735 79 0.42105263 2 -0.495 150 108 11 19 0.01592593 62.790697 67 0.57894736 8 -0.72 100 100 19 19 0.02 50 1 -1

the di/do produced a higher value than hi/ho. Reasons for this discrepancy could be inaccurate measuring tools and procedures. A small ruler and a pair of eyes were used to measure the hi and ho, so therefore the measurements could’ve been inaccurate. In Part D, the effect of lenses on images and objects was measured using a crossed arrow target, convex lens, viewing screen, and lightsource. The crossed arrow target was placed in front of the light source at a distance, do, away from the viewing screen. As the do changed with every trial, the convex lens would move until a clear and focused image could be seen on the viewing screen. This distance is referred to as di in Data Table 4. As the do increased, the di would also increase until no data could be found because the di would surpass the do. When we asked the Lab TA about this issue and got the Lab TA to view our experiment and help us, no solution was determined therefore part of our data is inconclusive. Reasons for this could be because the focal length extended past the mirror or the initial distance between the crossed arrow target and lightsource wasn’t enough. Using the rest of the data in Data Table 4, the focal length, f, and magnification of the reflected image, m, were calculated. The focal length increased as do decreased and di increased. Similar to Part C, hi/ho and di/do produced similar results, however this time the absolute value of hi/ho was greater than that of di/do. Conclusion: In this experiment, we explore the laws of reflection and refraction using a small lightbulb, arranged slotted tiles and both mirrors and lenses. The law of reflection states that the angle of incidence, the angle between the ray of light and the normal vector, is equal to the angle of reflection, the angle that the reflected ray of light makes. Table 1 indicates that our results correspond with this law. Table 2 and graphs 1 and 2 describe our results studying the law of refraction. We calculated approximately 1.14 for our calculated index of refraction of the acrylic in which the light refracted. In graphs 1 and 2, we can see that our data is roughly linear, and the indices of refraction and incidence are positively correlated. Table 3 and 4 depict the reflected or refracted image distance from the image object, and the height of each image. In data table 3, we were successfully able to demonstrate the Thin Lens Equation, using the relationship between do and di with f, the focal length. We found that as di decreased, the focal length increased. The image was magnified each time the di was decreased. In table 4, the inverted image was reduced. As the di increased, the focal length increased as well. Beginning approximately at do=300, our image was not clearly focused on the viewing screen. Data was only collected until do=250 due to the nature of the experiment, and the inability to recreate more precise adjustments, as explained in our analysis.